I've salvaged some aluminium sheet courtesy of my skip-yard owning father-in-law but am not sure if it's appropriate to use for the floor of my Roadster.

Bascially it's an old pub sign, approx 3mm thick and about 5ft by 4ft. Is there any good reason I can't use it for the floor of my car? A quick look online suggests to me that i'll be paying roughly £100 for an equivalent sized sheet of new alu so I am keen to use it if I can....! I'd also like to then use similar material for the end of the passenger footwell and the bulkhead panel...

Make the floor in one piece and just cut the bell housing part out it will add some much needed stiffness to the chassis. If using an angle grinder and slitting disk to cut the sheet wear a mask as ali dust is a known cause of erm..err..oh...alzheimer's.

I used 3mm aluminium, cut into the std coffin type shape for each side... I know there are a lot of comments for and against but this is what I did given the material I had, if you want a pic let me know